Native Plant Growers – Swallowtail Butterflies Are Returning to Civic Park

Swallowtail Butterflies Are Returning to Civic Park

by Robin Wolf

The next time you come to the Civic Park Community Center, you might want to look for Swallowtail butterflies along the creek. These large yellow and black butterflies began returning to the creek bank after habitat restoration got under way. The WC Watershed Council has removed invasive ivy over a 200 foot stretch of the creek bank and replaced it with native fescue grass. As a result, Swallowtail butterflies are retuning to the creek area.

Swallowtail butterflies like to lay their eggs on the leaves of the valley oaks and coast live oaks that line the creek. Caterpillars hatch and eat those leaves. Then when full-grown, the caterpillars drop to the ground to make a chrysalis from which a butterfly will emerge. If the caterpillar drops into ivy, the chrysalis and emerging butterfly will probably be lost. The butterfly may emerge too deep in the ivy to be able to climb out without damaging her delicate wings. Butterflies only lay their eggs on native plants and ivy is not native. Thus, she will not be able to lay her eggs on ivy to create the next generation. However, when the native plant habitat is restored, the caterpillars drop into native grasses and can finish their life cycle.

If you take your grandchildren to Civic Park and happen to see a swallowtail, please ask them not to chase or touch the butterflies.